668771408 has 10 divisors (see below), whose sum is σ = 1295744634. Its totient is φ = 334385696.

The previous prime is 668771333. The next prime is 668771423. The reversal of 668771408 is 804177866.

It can be written as a sum of positive squares in only one way, i.e., 539539984 + 129231424 = 23228^2 + 11368^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20899091 + ... + 20899122.

Almost surely, 2^668771408 is an apocalyptic number.

It is an amenable number.

668771408 is a deficient number, since it is larger than the sum of its proper divisors (626973226).

668771408 is a wasteful number, since it uses less digits than its factorization.

668771408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41798221 (or 41798215 counting only the distinct ones).

The product of its (nonzero) digits is 451584, while the sum is 47.

The square root of 668771408 is about 25860.6149965541. The cubic root of 668771408 is about 874.4988294093.

The spelling of 668771408 in words is "six hundred sixty-eight million, seven hundred seventy-one thousand, four hundred eight".